Image : Gliders Tracked Potential for Oil to Reach the East Coast

The Loop Current is a big current of warm water (orange) that comes from the Caribbean Sea between the Yucatán Peninsula and Cuba into the Gulf of Mexico. It often loops up relatively close to Louisiana and then back down and through the Florida Straits and feeds the Gulf Stream. In the early days of the Deepwater Horizon crisis, officials feared the Loop Current could carry oil from the spill up the U.S. East Coast. In winter, satellites can detect the warm Loop Current, which contrasts with cooler Gulf of Mexico waters. But it gets harder to discern as the shallow Gulf warms up in summer. (Ocean Remote Sensing Group, Johns Hopkins University Applied Physics Laboratory)